This invention relates in general to a blood clot filter and more particularly to one that can be inactivated without being removed from the vascular lumen.
Blood clot filters of the type disclosed herein are normally deployed in the inferior vena cava. It is known in the art to have permanent blood clot filters, temporary blood clot filters and blood clot filters which can be converted from being a filter to a non-filtered state without requiring removal thereof.
There are known advantages and drawbacks to each of these three types of filters and each has its appropriate role.
A large number of different blood clot filter designs are known for various techniques that provide various degrees of centering, filter efficiency, blood flow characteristics and ease or difficulty of removal. Certain filters are designed so that the filter can be left in the patient when the filtering function is no longer required.
Because the various desirable characteristics of a blood clot filter are partially contradictory or antagonistic toward one another, it is desired to provide a filter which has an optimum trade-off of the various desirable characteristics.
It is one purpose of this invention to provide a blood clot filter which can be placed into a disabled state and left in the patient when the filtering function is no longer required.
It is a related purpose of this invention to provide a blood clot filter that will be centered in its filter state.
It is a further purpose of this invention to provide the above two purposes in a design that provides an optimum trade-off of blood flow, filter efficiency and the structural tensions necessary to maintain the filter centered in its filtered state.
It is a further object of this invention to provide the above objections in a device which is relatively easy for the surgeon to implant at a desired site.
It is a further purpose of this invention to provide a filter design which will catch blood clots that pose a risk and that will do so in a fashion which minimizes the chance of having the blood clots accumulate and block the flow through of blood at the site.